How Much Does a Fractional CTO Cost? UK Rates, Pricing Models, and the Numbers Nobody Talks About

Let's get to the numbers.

A fractional CTO in the UK currently costs between £800 and £1,600 per day, or £3,000 to £8,000 per month on retainer. The wide range comes down to experience, location, specialisation, and how many days per week you need them.

But the raw rate doesn't tell you much on its own. After twenty-five years of building startups — first as an agency, then as equity co-founders — we've learned that the sticker price is the least interesting part of this conversation. What matters is what you get back, and how the commercial model shapes the relationship.

UK day rates in 2025-26

The market has settled into fairly predictable bands:

Seed and early stage (£800-£1,000/day).: Experienced technologists with 10-15 years in the industry who are comfortable working with very early companies. At this rate you get someone who can define your architecture, help hire your first developers, and keep an outsourced team honest. They might not have a string of exits, but they've built real products that real people use.

Growth stage (£1,000-£1,250/day).: More experience, more pattern recognition, probably a couple of CTO roles behind them. They've seen what happens when early architectural shortcuts come back at scale, because they've lived through it. They're also better at the investor-facing side — articulating your technical strategy in a way that makes VCs comfortable.

Senior / specialist (£1,400-£1,600+/day).: Multiple exits. Deep domain expertise — fintech, AI/ML, cybersecurity, platforms that need to handle millions of users. If you're in a regulated industry or building something technically complex, this is where you're looking. These rates have climbed 15-25% since 2023.

Monthly retainers

Most engagements run on monthly retainers rather than day rates. It's simpler — you know what you're paying, they know what they're earning, and nobody's watching the clock.

• 1 day per week:: £3,000-£5,000/month
• 2 days per week:: £5,000-£8,000/month
• 3 days per week:: £8,000-£12,000/month

London rates are consistently 20-30% above the rest of the UK. If your fractional CTO can work remotely — and most can — being based in Manchester, Edinburgh, Birmingham, or anywhere outside London saves real money without sacrificing quality.

The full-time comparison most people get wrong

When founders weigh up a fractional CTO against hiring full-time, they almost always underestimate the full-time cost. Here's what a London-based CTO actually costs in year one:

| Cost | Low estimate | High estimate |

|------|-------------|---------------|

| Base salary | £120,000 | £160,000 |

| Employer's NI (13.8%) | £16,560 | £22,080 |

| Pension (5%) | £6,000 | £8,000 |

| Benefits (health, life, etc.) | £3,000 | £6,000 |

| Equipment and software | £3,000 | £5,000 |

| Recruitment fees (20% of salary) | £24,000 | £32,000 |

| Onboarding ramp-up (3 months reduced output) | £20,000 | £30,000 |

| Total year one: | £192,560: | £263,080: |

The recruitment fee disappears in year two, but you're still looking at £148k-£201k annually.

And there's a cost that never shows up in spreadsheets: risk: . If the hire doesn't work out — and at the senior level, a meaningful percentage don't — you've spent months of salary, a recruitment fee you'll never see again, and you're starting over. Some estimates put the cost of a failed senior hire at 2-3x annual salary.

A fractional CTO at two days a week? About £72k per year. No recruitment fees. No employer's NI. No pension. No risk of a six-figure hiring mistake.

The pricing model nobody was talking about five years ago

Day rates and retainers are the standard models, and they work fine for a lot of situations. But there's a third model that's growing fast, and we think it's often the smartest option for early-stage startups.

The equity-aligned model.:

Instead of paying full commercial rates, you combine a reduced fee with an equity stake. The CTO works at 50-70% of their normal rate in exchange for ownership in the company — anywhere from 1-5% for a fractional role, or 10-25% for a full technical co-founder partnership.

We moved to this model ourselves after years of pure consultancy, and the difference in how it changes the relationship is night and day.

When you're paying someone £1,200 a day, they're incentivised to keep billing. When they own part of the company, they're incentivised to build something that works — and to do it efficiently. They'll push back on unnecessary features because wasted development time is money coming out of their pocket too. They'll care about your unit economics because it affects their return. They'll still be thinking about your architecture at 9pm on a Tuesday, not because they're on the clock, but because they have a stake in the outcome.

Why it works for founders:: You conserve cash. At the early stage, cash is almost always your scarcest resource, and anything that reduces your burn rate without reducing the quality of your team is worth considering. A hybrid arrangement might save you £30k-£60k per year in cash compared to pure consultancy, and the CTO has every reason to make the company succeed.

Why it works for CTOs:: They get upside. A day rate caps their earning at whatever the retainer is. An equity stake in a company that exits for £20m is a very different outcome. The best fractional CTOs — the ones with twenty years of experience and multiple exits — are increasingly choosing equity-aligned work over pure cash. It's a signal of confidence.

What to watch out for:: Equity terms need to be properly structured. Standard four-year vesting with a one-year cliff. Clear definitions of what triggers acceleration. A proper shareholders agreement, not a handshake. We've seen equity arrangements go wrong when the terms aren't spelled out upfront, and it's always worse than the awkwardness of getting a lawyer involved early.

What pushes rates up

Regulated industries.: Fintech, healthtech, defence — anything touching payment data or patient records. The compliance burden is significant and the CTO needs to understand the regulatory landscape, not just the technology.

Urgency.: If your CTO has just walked out and you need someone on Monday, expect a premium. Planning ahead saves money.

Investor-facing work.: Board presentations, due diligence preparation, and investor meetings are a different level of engagement than quietly managing a dev team.

AI/ML expertise.: The market for genuine AI capability — not people who did a weekend course — is brutally competitive right now. Rates reflect that.

What pushes rates down

Location flexibility.: Remote CTOs based outside London charge 15-25% less for equivalent experience.

Longer commitments.: A twelve-month engagement usually gets a better rate than month-to-month. Income certainty is worth a discount.

Equity alignment.: As discussed above, a CTO taking equity alongside a reduced rate can cut your cash costs substantially.

Stage of company.: Many experienced CTOs genuinely enjoy early-stage work and will adjust rates for pre-revenue startups with interesting problems. It doesn't hurt to ask — especially if you're offering equity alongside.

The cost nobody talks about

There's one cost that dwarfs everything on this page: making bad technology decisions because nobody with enough experience was in the room.

Choosing the wrong stack. Hiring the wrong lead developer. Letting technical debt pile up until a rewrite is the only way forward. Failing a due diligence review and losing an investment round.

We've seen the "rebuild from scratch" scenario cost companies £300k-£500k. More than once. CB Insights reports that 23% of startup failures are attributed to the wrong team, and your early technical decisions compound over time. Get them right and you're building on solid ground. Get them wrong and you spend years paying for it.

A fractional CTO's monthly retainer — or a co-founder's equity stake — looks very different when you weigh it against the cost of rebuilding a product because the original architecture couldn't handle growth.

So what should you budget?

For a UK startup at seed or early growth stage:

• Light touch advisory:: £1,500-£2,500/month. A few hours per month for strategic guidance and architecture reviews. Good if you're reasonably technical yourself and mainly want a sounding board.
• Standard fractional CTO:: £4,000-£7,000/month for one to two days per week. Enough to be genuinely embedded — attending standups, running technical interviews, making architecture calls.
• Heavy involvement:: £8,000-£12,000/month for three days per week. Approaching the output of a full-timer at a fraction of the cost.
• Equity-aligned partnership:: £2,000-£4,000/month cash plus 1-5% equity (fractional) or reduced rates plus 10-25% equity (technical co-founder). Conserves cash, aligns incentives, but requires genuine long-term commitment from both sides.

The right model depends on what you're building, how much cash you have, and how much alignment you need. There's no single answer, and anyone who tells you otherwise is probably selling you something.

Read next:: What is a fractional CTO? — the full practical guide, or CTO as a Service explained — how the engagement model works in practice.

Cooply is a technical founding team based in South Wales and Yorkshire. We partner with startups as equity co-founders, fractional CTOs, or on a hybrid basis — taking on 3-4 new ventures each year. We're not the cheapest option, but we bring 25+ years and 25+ exits to every engagement. If you'd like to understand what the right model looks like for your business, let's talk.